This invention relates to new and improved molded egg cartons which may be formed from pulp or plastic foam or the like. More particularly, this invention relates to egg cartons which have specially formed structure in the carton cover to provide a strong load-resistant cover while at the same time making provision for openings or windows through which eggs loaded in the cartons may be viewed. The improved cartons are molded of pulp or foam in open position with the tops of the covers in generally the same plane as the bottoms of the egg cells in the tray portions of the cartons. The egg cells are oriented in a manner different from prior constructions in order to strengthen the cartons and cooperate with other elements in accordance with the invention.
In general, when the cartons are made of molded pulp, they are formed on one side of a shaped screen so that a carton thus formed may be said to have a screen side, which is usually the outside of the carton, and a bark side, which is usually the inside of the carton. In general, when the cartons are made of plastic foam, they are usually thermo-formed or vacuum-formed. In the thermo-forming process and vacuum-forming process a flat sheet of foam is drawn against a shaped mold under the influence of heat and vacuum or heat and pressure.
In the past egg cartons have been made in the configuration of two rows of three eggs, two rows of five eggs, two rows of six eggs and three rows of four eggs. In some instances, a set of threes has been molded as a unit. Egg cartons have been produced both with and without locking flaps. In general, locks on egg cartons include a projection or button formed on either the tray portion or a locking flap associated with the tray and which cooperates with a hole or orifice in the front wall of the cover. In general, cartons are provided with two locks. However, in some instances cartons have been provided with more than two locks.
As shown in U.S. Pat. No. 2,771,233, the master carton designer, Cox, produces a square bottom egg cell which became known as the Case-Ace Egg Cell. The Cox egg cell, in its time, was considered to be the finest egg cell in any egg carton. In Cox's egg cell, the sides of the square on the bottom were parallel to the long front and rear sides of the carton and also parallel to the two short ends of the carton. The lower portion of Cox's egg cell comprise planar sections which extend upwardly and outwardly to merge an arc with an upper conical section. Cox referred to his lower cell wall portions as polygonal and to his upper wall portions as rounded and conical. Cox postulated that his egg cell lower flat surfaces provided effective cushioning and the conical upper portions served to confine the egg therein at its zone of greater girth.
As shown in U.S. Pat. No. 2,990,094, the master carton designer Reifers, in his improved carton which received wide acceptance, adopted the Case-Ace Egg Cell developed by Cox, and included a hinged locking flange provided with buttons or projections which cooperate with holes in the front wall of the cover.
As shown in U.S. Pat. No. 3,362,605, the master carton designer, Bixler, adopted the Case-Ace Egg Cells developed by Cox and the button lock on the locking flange which cooperate with orifices or holes in the front wall of the cover as developed by Reifers. Bixler provides windows in the cover so that the eggs in the carton may be viewed. The U.S. Patents to Bixler, U.S. Pat. Nos. 4,025,038 and 4,059,219 illustrate Bixler's further developments in egg cartons of the type illustrated in his earlier patent, U.S. Pat. No. 3,362,605.
The U.S. Patent to Alsman U.S. Pat. No. 3,217,963, discloses a 2.times.6 egg carton in which he, too, adopted the Case-Ace Egg Cell developed by Cox. However, Alsman utilized a lock which was different from that of Reifers in that Alsman's carton did not include a locking flap. Alsman provided a locking post which extends upwardly from the front wall of the tray and was adapted to cooperate with an opening in the front wall of the cover.
Friday in his U.S. Pat. No. 3,245,600 discloses a 2.times.6 egg carton including open ended posts on the front wall of his tray portion which were intended to cooperate with orifices in the front wall of his cover, and, in this regard, Friday endeavored to follow Alsman. The U.S. Patent to Hartmann et al U.S. Pat. No. 3,276,656, illustrates a 2.times.3 egg carton in which a projection extending upwardly from the tray portion was intended to cooperate with an opening or aperture in the wall of the cover. Hartmann et al generally follows the teaching of Alsman. The U.S. Patent to Seest et al, U.S. Pat. No. 3,471,078, is very similar to Hartmenn et al and discloses a 2.times.3 egg carton having a domed up post which was intended to cooperate with an opening or orifice in the cover wall. The very top of the dome in the Seest et al patent is provided with a generally horizontal rib. The design of the carton in Seest et al follows Hartmann et al and they both utilize a lock following thee lock design of Alsman.